Neuroplasticity in Auditory Aging_Project 2 Aims 1 and 2

University of Maryland

Status: Completed

Conditions: Auditory Perceptual Disorders; Aging Problems

Treatments: Behavioral: Auditory training: temporal cues

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT03475043

P01AG055365 (U.S. NIH Grant/Contract)

UMDCP_P01P2

Details and patient eligibility

About

Millions of elderly adults in the USA have age related hearing loss (ARHL), a malady that affects half of adults 60-69 years, and the majority of older adults. This hearing loss not only impacts communication and functional ability, but also is strongly associated with cognitive decline and decreased quality of life. This project aims to develop effective strategies to compensate and reverse this process through a deeper understanding of plasticity and adaptive auditory function, and how to engage it and harness it to remedy ARHL.

Full description

The detrimental effects of aging on auditory temporal processing have been well documented in humans and animal models. At present, there are gaps in knowledge of the extent to which these auditory temporal processing deficits can be mitigated in older adults with or without hearing loss through auditory training and neuroplasticity, to improve precision of neural timing and speech understanding. The long-term goal is to determine the extent to which hearing deficits in older adults can be ameliorated with auditory training. The investigators propose an innovative approach to the investigation of aging, hearing, and neuroplasticity by marrying perceptual training experiments with electrophysiological measurements. The objectives are to compare young normal-hearing (YNH), older normal-hearing (ONH), and older hearing-impaired (OHI) adult listeners, and evaluate the improvements in perceptual and electrophysiological measures of temporal processing after explicit training on auditory temporal processing tasks. The central hypothesis is that training of auditory temporal processing will produce concomitant improvements in both perceptual performance and neural encoding, which will close the gap in the age-related differences between groups. The central hypothesis will be tested by pursuing two specific aims: (Aim 1) Determine the extent to which perceptual training on temporal rate discrimination using simple non-speech stimuli improves perceptual and neural encoding in YNH, ONH, and OHI listeners; and (Aim 2) Determine the extent to which perceptual training on the processing of sentences with increasing presentation rate can improve behavioral performance and neural encoding in YNH, ONH, and OHI listeners. The expected outcomes are that the investigators will learn what perceptual training tasks lead to simultaneous improvements in perceptual and neural auditory temporal processing and the findings will produce a significant impact in older listeners who experience difficulty in communicating in daily life because they will lead directly to focused and novel forms of rehabilitation. This research is innovative because the investigators will have established techniques that are proven to provide significant improvements in auditory temporal processing and speech perception, combined with evidence of improvements to neural encoding. These studies will serve the larger goals of the program project grant because they will help identify the neuroplastic mechanisms in the brain of humans that correspond to successful behavioral outcomes in younger and older adults.

Enrollment: 405 patients

Sex: All

Ages: 18 to 85 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• native speaker of English
• normal cognitive function as measured on Montreal Cognitive Assessment
• pass screening auditory brainstem response test to make sure they have recordable brainwaves to acoustic stimuli
• age and hearing sensitivity:
• young normal-hearing listeners, 18-35 years, hearing thresholds less than 25 decibels (dB) HL from 250 - 4000 Hz;
• older normal-hearing listeners, 65-85 years, hearing thresholds less than 25 dB HL, from 250-4000 Hz;
• older hearing-impaired listeners, 65-85 years, with mild-to-moderate, high frequency sensorineural hearing loss;
• high school diploma

Exclusion criteria

• absence of conductive hearing loss and middle-ear disease
• no neurological disease
• severe or profound hearing loss
• non-native speaker of English
• cognitive impairment

Trial design

Primary purpose: Health Services Research

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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405 participants in 3 patient groups

Auditory training: temporal cues

Experimental group

Description:

Aim 1: Listeners will hear target acoustic stimuli that vary in a temporal (timing/duration) cue for 9, 1-hour training sessions and will receive correct-answer feedback. Aim 2: Listeners will hear sentences that vary in speech rate for 6, 1-hour training sessions and will receive correct-answer feedback.

Treatment:

Behavioral: Auditory training: temporal cues

Auditory training: non-temporal cues

Active Comparator group

Description:

Aim 1: Listeners will hear target acoustic stimuli that vary in either stimulus intensity or stimulus frequency during 9, 1-hour training sessions and will receive correct-answer feedback. Aim 2: Listeners will hear speech in varying levels of noise during 6, 1-hour training sessions and will receive correct-answer feedback.

Treatment:

Behavioral: Auditory training: temporal cues

Passive control group (Aims 1 and 2)

No Intervention group

Description:

Listeners will be evaluated on pre-training and post-training tests, but will receive no training at all.